Study On Dynamic Speed Limit Method Of Freeway Under Different Visibility Conditions In Foggy Weather

At present,China is in a new period of rapid economic development.The mileage of highway construction has been rising year by year.When people enjoy the fast,economical,and efficient services of the expressway,the traffic safety issue is still a major issue for transportation.Under conditions of abnormal weather conditions,such as low visibility weather in fog days,traffic safety issues are particularly acute.Therefore,in-depth studies on traffic safety under low-visibility weather conditions on highways in foggy days are conducted.From the perspective of the human-vehicle–road-environment system,key factors affecting traffic safety are identified,and effective measures to solve safety problems are proposed to guarantee that the operational management fees for traffic safety issues are used scientifically and reasonably.The dissertation focuses on the vehicles running under different visibility conditions of highway fog,using the three-dimensional driving simulation method to design a single-factor and multi-factor comprehensive experimental scheme,and using the principles and methods of mathematical statistics to carry out the driving behavior characteristics of drivers.Analyze and evaluate,analyze the vehicle's lateral displacement characteristics in the case of visibility,round curve radius,and vehicle speed and their different levels of combination,and thus establish a dynamic speed limit model under different visibility conditions on the highway.In the context of the current rapid development of expressways and traffic safety problems in fog and sky,the paper comprehensively analyzes the current research status and research results in the related research fields at home and abroad;the visibility of this study from the perspective of the process of fog formation and visibility The scope is defined;statistical analysis is performed on the data of existing highway fog accidents,and the characteristics of fog accidents and the effect of fog on traffic safety are searched;the indicators that are commonly used in traffic safety analysis and evaluation are compared and the application is proposed.For the analysis of the new characteristics of the thesis(vehicle lateral offset coefficient);In order to construct a three-dimensional driving environment for the highway in foggy day,a comparison was made of commonly used simulation software,and finally UC-win/Road was selected from the perspective of highway design.Highway fog driving environment;from the perspective of experimental purposes,experimental equipment,experimental personnel,experimental data collection,the paper designed the experimental program for research,including single-factor and multi-factor comprehensive experiments,and finally completed using a driving simulator.The entire experiment;from the perspective of driving behavior,analysis In this experimental scheme,visibility,round curve radius and running speed affect the vehicle lateral offset characteristics,and the strength factors of each influencing factor are ranked;a multi-factor-based dynamic speed limit model is established,and the design speed is 80 km/h.The speed limit of the expressway is recommended.This article enriches the theories and methods for the safety of freeway on fog days,and provides a theoretical basis for the development of speed management strategies for expressway management departments under the conditions of fog days on freeway.To a certain extent,it can reduce the occurrence of traffic accidents or reduce the severity of accidents.And the losses it brings are conducive to accelerating the sustainable development of transportation construction.It has important practical application value and social significance.